Objective: The purpose of the present research was to investigation of the effectiveness social competence instruction on the adaptation behavior of 12-14 years old boy students with intellectual disability in Tehran province.

Materials & Methods: This research was quasi experimental with pre-test and post-test design with control group. The study population included of 12-14 years old boy students with intellectual disability in Tehran province. The participants were chosen by cluster sampling method from two districts of Tehran province. Then, from each districts were chosen one school and from each school were chosen 20 boy students with Intellectual disability by randomly method. They were divided in experimental and control group. for experimental group were used social competence instruction in the 10 instructional sessions but the control group did not receive none of instruction. The instruments consist of Riven intelligence test, Vineland adaptive behavior scales and social competence instructional program. The data analysis was done by using MANCOVA.

Results: The findings of this research showed that there was significant increase in adaptive behavior scores of experimental group in comparison with control group (P<0.0005). Also adaptive behavior scores of experimental group was significantly in communication skill, life skill and social skill (P<0.0005), But was not significantly in kinetic (P<0.269).

Conclusion: The social competence instructional program led to improve the adaptive behavior, communication skill, life skill and social skill of students with intellectual disability. Therefore, planning for providing of social competence instruction is a particular importance.